Everyone always talks about the wonders of space: its vastness, its complexity, and how exploring it is stretching the limits of human endeavor. Oddly, nobody ever talks about what astronauts do with their poop.

Fortunately, Minute Physics and Smarter Every Day aren't afraid to tackle such questions. In this video, they explore problems you probably never thought existed: how ejecting urine from a spaceship changes its trajectory, and how astronauts preferred to leave poop on the moon in order to bring back more rock samples. You're welcome. [YouTube]